Process of treating ores.



(No Model.)

Patented ma 27, I902.

c. J. BEST.

PROCESS OF TREATING OBES.

(Application filed. July 26. 1901.)

m: uonms PETERS co. FHOTO-LITHO, WASMNGTON, o c

UNTTnn STATES PATENT OFFICE.

CHARLES J. BEST, OF DENVER, COLORADO.

PROCESS OF TREATING ORES.

.SlEGIFICATION forming part of Letters Patent No. 701,13 dated May 27,1902.

Application filed July 26, 1901- Serial No. 69,744. (No specimens.)

To all whom it may concern.-

Be it known that I, CHARLES J. BEST, a citizen of the United States,residing at Denver, in the county of Arapahoe and State of Colorado,have invented a certain new and useful Improvement in Processes andCompounds for Treating Ores, of which the following is a specification.

My invent-ion relates to processes and compounds for extracting preciousmetals from their ores.

I have shown diagram matically an arrangement of devices by means ofwhich my process could be carried out, though it will be understood thatthese are merely diagrammatic, and I have not undertaken to show theconstruction of the several parts more than to merely suggest theirrelation to each other for the purpose of carrying out the process.

A indicates a crusher adapted to receive and crush any kind of ore, andany style,form, size, and shape of crusher will suffice. It isassociated with the screen B, which is preferably, approximately, afifty-mesh screen. The ores having thus passed the fifty-mesh screen aredischarged into a tank 0, wherev they are indicated at D.

E is a mixing-vat in which the solution to which the ground ore is to betreated is prepared. =This solution consists of certain salts,hereinafter more particularly referred to, a certain quantity of water,and a certain per cent. of acid, the proportions of these threesubstances differing according to the requirements ofanyparticularcase.These products are preferably mixed together separatelyas, for example,in the mixer E, whence they are discharged into the tank 0 until the oreD in the bottom thereof is covered. The height of the solution in thetank is indicated by F.

G is a pipe by which steam may be injected into the tank to heat thecontents. The liquid should be kept in a boiling state in the tank forfrom one to two and a half hours, according to the strength of the oreor the requirements of the particular case. This process results inthedissolving out of the precious metals in the ore by the salt solution,and the solution so charged is now drawn off, preferably through thefilter I-I, into the precipitator J. In this precipitator the metals areto be precipitated, and this is done by discharging sulfureted hydrogengas from the reservoir or gas-producer K into the precipitator. Theresult is that a sulfid precipitate is formed which contains theprecious metals, and the solution discharged on the precious metals maybe again used in the same manner, it being properly strengthened, ifnecessary, by the addition thereto of more or less of its originalelements. The sulfid precipitate is drawnotf into the pan L,where by asuitable application of heat with the ordinary fluxes the gases aredriven away and the metals left behind.

The heating of the substances in the tank 0 may be accomplished in anydesired manner, though I have suggested that it be done by dischargingsteam therein.

It will be observed that more heat alone is not used; but thesulfid-ores are roasted and then the solution is applied, and by theaction of such solution the metals are extracted or reduced to sulfidprecipitates. When the sulfid ores are roasted, they becomesulfates bythe action of the heat. The sodium ch10 rid in the solution which Iemploy dissolves the silver chlorid formed by the action of the chlorinon silver, and thus the solution dis solves out the gold, silver, andcopper, and they remain in solution until precipitated by the action ofsulfid gas. This action is somewhat similar to the action of aqua regia.

The salts used to make the salt mixture are as follows, each being usedin approximately the proportions indicated: two parts common salt, oneand one-fourth parts niter, one and one-fourth parts alum, and one andone-half parts nitric acid. These figures are approximate, and theseproportions may be somewhat varied or equivalents Varying in pro portionsomewhat might be employed for the various parts of this salt mixture.This is what I call my salt mixture, intending by these words to referto the compound last above described.

I do not wish to be limited to the precise number of salts used or totheir particular description but salts having qualities simi lar to thequalities of the salts indicated and used in proportions capable ofbringing about the results accomplished by the salts used in theproportions above indicated I consider within the scope of my invention.

I prefer to prepare my compound of salts or salt mixture as a dry massand then add it to the solution of water and acid in the mixer E.

I have suggested diagrammatically that the solution after theprecipitate is formed may be pumped back into the mixer from the tank Jfor reuse and also that the vapors driven off from the pan L by the heatmay be carried back in like manner to the mixer E, thus to avoid theloss of the active principle of the salts. The metal alone may be drawnoff from the bottom of the pan.

My preparation is suitable for operating in connection with orescontaining copper, iron, silver, and gold, but not with ores containinglead. The heating proposed for the solution causes it to work much morerapidly and to bring out a larger per cent. of the metal. The solutioncan even be applied to take out almost any other metal other than-lead.It is of course evident that the strength of the solution will have tobe varied as suggested, according to the kind of metal or metals to berecovered and the percentage of such metals in the ore under treatment.

After the sulfid precipitates are formed their further treatment issimple and any of the ordinary processes can be applied thereto. I havenot, therefore, included a description of these processes in my presentapplication.

I'claim- 1. The process of treating ores, which consists in grindingthem to a suitable fineness, supplying thereto a solution, consisting ofa large proportion of water, a small proportion of acid and a saltmixture, consisting approximately of two parts common salt, one andone-quarter parts niter, one and one-quarter parts alum and one andone-half parts nitric acid, boiling the whole for a proper length oftime, filtering the solution, precipitating the metallic portions by theapplication of sulfureted hydrogen to the filtered solution, until asulfid precipitate is formed, then heating such precipitate with theusual fluxes to drive 01f the vapors, then drawing off the metals, andthen returning such solution and vapors for use in the heating-tank.

2. The process of treating ores, which consists in grinding them to asuitable fineness, supplying thereto a solution, consisting of a largeproportion of water, a small proportion of acid and a salt mixture,consisting approximately of two parts common salt, one and one-quarterparts niter, one and one-quarter parts alum and one and one-half partsnitric acid, boiling the whole for a proper length of time, filteringthe solution, precipitating the metallic portions by the application ofsulfureted hydrogen to the filtered solution, un til a sulfidprecipitate is formed, then heat- :ingsuch precipitate with the usualfluxes to drive off the vapors, and then drawing off the metals.

3. The process of treating ores, which consists in grinding them to asuitable fineness, supplying thereto a solution, consisting of water,acid and a salt mixture, consisting approximately of two parts commonsalt, one and one-quarter parts niter, one and onequarter parts alum andone and one-half parts nitric acid, boiling the whole for a properlength of time, filtering the solution, precipitating the metallicportions by the application of sulfureted hydrogen to the filteredsolution, until a sulfid precipitate is formed, then heating suchprecipitate with the usual fluxes to drive 03 the vapors, and thendrawing off the metals.

4. The process of treating ores, consisting of applying to theproperly-ground ores a solution of from one to two parts acid, seventyto eighty parts water and nineteen to twentyfive parts salt mixture,consisting approximately of two parts common salt, one and onequarterparts niter, one and one-quarter parts alum and one and one-half partsnitric acid, then boiling the compound for from one to two and a halfhours, then drawing oif the solution and causing a precipitation of themetallic portions to form a sulfid, then by the application of heat withthe usual fluxes freeing the metals from the substances with which theyare associated by reason of the preceding steps in the process.

5. The process of treating ores, consisting of applying to theproperly-ground ores asolution of acid, water and a salt mixture,consisting approximately of two parts common salt, one and one-quarterparts niter, one and one-quarter parts alum and one and one-half partsnitric acid, then boiling the compound for from one to two and a halfhours, then drawing off the solution and causing a precipitation of themetallic portions to form a sulfid, then by the application of heat withthe usual fluxes freeing the metals from the substances with which theyare associated by reason of the preceding steps in the process.

6. The process of treating ores, which consists in grinding them to asuitable fineness, supplying thereto a solution consisting of water,acid and a salt mixture, consisting approximately of two parts commonsalt, one and one-quarter parts niter, one and onequarter parts alum andone and one-half parts nitric acid, boiling the whole for a properlength of time, precipitating the dissolved metals as sulfids, thenheating such precipitate with the usual fluxes to drive off the vapors,and then drawing off the metals.

CHARLES J. BEST.

Witnesses:

E. O. BET-rs, CAIN NERO.

ICO

